Waveshare Audio Driver HAT REV2

Product Overview

The Audio Driver HAT REV2, produced by Waveshare Electronics, is an audio expansion board featuring the ES7210+ES8156 dual Codec solution. It supports 4-channel circular microphone recording, dual-channel audio playback, audio loopback, and more. The board is shown below:

For detailed information about the audio sub-board, please refer to the Audio Driver HAT.

Installation

• Hardware Setup

1. Connect the expansion board to the 40-pin header of the RDK X3 as shown below.
   

2. Run the command cat /sys/class/socinfo/som_name to check the board type, and set the DIP switches on the audio sub-board accordingly:

   • If the returned value is 5 or 6, set all three DIP switches to the ON position.
   • If the returned value is 8, set all three DIP switches to the OFF position.

• Software Configuration

1. Use srpi-config to configure the audio board.
   Go to 3 Interface Options -> I5 Audio
   Select Audio Driver HAT V2:

2. Follow the prompts to execute the reboot command, or run sync && reboot to restart the board. If cat /proc/asound/cards shows a sound card other than duplexaudio, the expansion board is installed successfully.

root@ubuntu:~# cat /proc/asound/cards 
 0 [duplexaudioi2s1]: simple-card - duplex-audio-i2s1
                      duplex-audio-i2s1
 1 [duplexaudio    ]: simple-card - duplex-audio
                      duplex-audio

• Uninstallation

1. Use srpi-config to configure the audio board.
   Go to 3 Interface Options -> I5 Audio
   Select UNSET to uninstall the audio driver and related configurations.

2. Remove the expansion board.

Usage

Check if the sound card exists and verify the device number.

To confirm the sound card is registered (as mentioned above):

root@ubuntu:~# cat /proc/asound/cards 
 0 [duplexaudioi2s1]: simple-card - duplex-audio-i2s1
                      duplex-audio-i2s1
 1 [duplexaudio    ]: simple-card - duplex-audio
                      duplex-audio

To check logical devices:

root@ubuntu:~# cat /proc/asound/devices
  2: [ 0- 0]: digital audio playback
  3: [ 0- 1]: digital audio capture
  4: [ 0]   : control
  5: [ 1- 0]: digital audio playback
  6: [ 1- 0]: digital audio capture
  7: [ 1]   : control
 33:        : timer

To check the actual device files in user space:

root@ubuntu:~# ls /dev/snd/
by-path  controlC0  controlC1  pcmC0D0p  pcmC0D1c  pcmC1D0c  pcmC1D0p  timer

From the above, and with reference to the Onboard Earphone Audio Port, you can confirm that sound card 0 corresponds to the Audio Driver HAT REV2 node; the devices exist, and the device numbers are 0-0 and 0-1. The actual devices to operate are pcmC0D0p and pcmC0D1c.

The onboard sound card corresponds to 1, with device number 1-0, which is not used here.

• Recording

• 2-channel microphone recording:

tinycap ./2chn_test.wav -D 0 -d 1 -c 2 -b 16 -r 48000 -p 512 -n 4 -t 5

• 4-channel microphone recording:

tinycap ./4chn_test.wav -D 0 -d 1 -c 4 -b 16 -r 48000 -p 512 -n 4 -t 5

• Playback

• Dual-channel audio playback (4-channel playback is not supported):

tinyplay ./2chn_test.wav -D 0 -d 0

• Audio Loopback Test

The playback loopback signal of this audio board uses recording channels 7 & 8, so you need to use the 8-channel recording command to capture it.

• Start 8-channel microphone recording

tinycap ./8chn_test.wav -D 0 -d 1 -c 8 -r 16000 -b 16 -t 3 -p 256

• Start dual-channel audio playback

tinyplay ./2chn_test.wav -D 0 -d 0

After recording, you can use audio software to check the spectrum information of channels 7 & 8 in the 8chn_test.wav file.

FAQ

For more questions, see this link